Hello
DISC Lite5 ac (bridge) ↔ (station bridge) SXTsq 5 ac
RouterOS: 6.46.6 (arm)
Firmware: 6.46.6
Band: 5GHz-only-AC
Channel Width: 80MHz
protocol:
802.11: 560Mb/s
Nv2: 420Mb/s
Nstreme 278Mb/s (very unstable)
Channel Width: 20MHz, 40Mhz - NSTREME unstable! 
On older mikrotik devices the nstreme protocol works stably, on those with ARM processor nstreme is very unstable, why ???
SimonG